Important Things You Should Know About Adult-onset Asthma

In most cases, the first symptoms of asthma occur during childhood. However, there are people who develop asthma later in life, and in these cases, we are talking about adult-onset asthma or late-onset asthma. Apparently, there is a steady increase in incidence of this type of asthma, most probably because advanced diagnostic and management techniques have resulted in prolonged longevity — more elderly people are now around.

Since this is a type of asthma, it makes sense to look at the similarities and differences in pathophysiology, clinical presentation, diagnosis, and treatment of childhood and adult-onset asthma.

What do adult-onset asthma and childhood asthma have in common?

Spirometry tests reveal decreased respiratory volumes, especially FEV1 (the volume of air exhaled during the first second of forced exhalation) and FEV1/FVC ratio, where FVC is the maximum volume of air that can be exhaled through forced exhalation after maximum inhalation.

The choice of medications is also similar in adults and children. Bronchodilators, such as beta-agonists (albuterol) and anticholinergics (ipratropium bromide) are commonly used. For alleviating inflammation in the airways, pulmonologists prescribe inhalatory corticosteroids. In case of intense asthma attacks, aminophylline injections can be administered intravenously, along with intravenous corticosteroids.

How is adult-onset asthma different from childhood asthma?

• Gender differences. Childhood asthma is more common in boys than in girls, and furthermore, boys usually have worse symptoms with more frequent hospitalizations. On the other hand, women have a higher incidence of adult-onset asthma than men, starting from late adolescence to menopause. During menopause, the risk decreases among women. This finding is confirmed in many studies and it suggests that female sex hormones may play an important role in the development of adult-onset asthma.
• Signs and symptoms. Although signs and symptoms are similar in children and adults with asthma, there is a difference in their frequency and intensity. Children often enjoy periods of relief from symptoms between asthma attacks. These periods are called remissions, and the lung function is normal during those periods. On the contrary, adult-onset asthma often presents with persistent symptoms of wheezing and chest tightness, with occasional asthma attacks. In most people with adult-onset asthma, full remissions with normal lung function are very rare.
• Risk factors. In children, atopic constitution (a tendency to develop allergies to multiple allergens) is commonly associated with asthma. Between 80 and 90 percent of children with asthma are sensitive to some inhalatory allergens. In adult-onset asthma, only about 30 percent of persons suffer from allergies, but there are other important risk factors, such as smoking, obesity, chronic cough, and air pollutants. Furthermore, people who had childhood asthma have a higher tendency to develop asthma again later in life.
• Diagnosis. Diagnosis of asthma is pretty much the same in children and adults. Anamnesis can be taken from patients or their parents, and then the doctor will perform a physical examination, including auscultation of the lungs. Spirometry, as well as other lung function tests, are always conducted in adults, but also in children older than five years. Because of the lack of remissions, adult-onset asthma can sometimes be mistaken for COPD (chronic obstructive pulmonary disease). The differential diagnosis can be hard in some cases.
• Response to treatment. As mentioned, similar medications are used in childhood and adult-onset asthma. However, the treatment is much more effective in children. Adult-onset asthma can be very stubborn and unresponsive to therapy, and it often requires using intravenous aminophylline and corticosteroids. Between asthma attacks, the lung function never really returns to normal, and there is always some degree of airway obstruction. Some adults with severe asthma require frequent hospitalizations.
• Drugs to avoid. Another problem which we face in adults, but not in children with asthma, is a limited ability to use some drugs due to contraindications and drug interactions. People who suffer from asthma should not take beta blockers, which are commonly prescribed for the treatment of hypertension and other cardiovascular condition. NSAIDs (non-steroidal anti-inflammatory drugs) are used in adults for a variety of indications, such as back pain, headaches, rheumatoid arthritis, etc., but in persons with asthma, they can significantly worsen the symptoms and frequency of asthma attacks. Aspirin is often prescribed to persons with some arrhythmias, coronary artery disease, and rheumatoid arthritis. Aspirin is also helpful for protecting bypass grafts and stents, and its daily usage in dosages of 75 to 100 mg has been proven to reduce the risk and mortality of heart attack and stroke. It is unfortunate that aspirin can worsen the symptoms of asthma, and should therefore be avoided.